Only reparse queries if the planner flags them for reparsing

src/backend/distributed/executor/multi_router_executor.c

@@ -325,7 +325,7 @@ ExecuteTaskAndStoreResults(QueryDesc *queryDesc, Task *task,
 	bool gotResults = false;
 	char *queryString = task->queryString;
 
-	if (isModificationQuery)
+	if (isModificationQuery && task->requiresMasterEvaluation)
 	{
 		PlannedStmt *planStatement = queryDesc->plannedstmt;
 		MultiPlan *multiPlan = GetMultiPlan(planStatement);

src/backend/distributed/planner/multi_router_planner.c

@@ -21,6 +21,7 @@
 #include "access/skey.h"
 #endif
 #include "access/xact.h"
+#include "distributed/citus_clauses.h"
 #include "distributed/citus_nodes.h"
 #include "distributed/master_metadata_utility.h"
 #include "distributed/metadata_cache.h"
@@ -710,6 +711,7 @@ RouterModifyTask(Query *query)
 	StringInfo queryString = makeStringInfo();
 	Task *modifyTask = NULL;
 	bool upsertQuery = false;
+	bool requiresMasterEvaluation = RequiresMasterEvaluation(query);
 
 	/* grab shared metadata lock to stop concurrent placement additions */
 	LockShardDistributionMetadata(shardId, ShareLock);
@@ -772,6 +774,7 @@ RouterModifyTask(Query *query)
 	modifyTask->anchorShardId = shardId;
 	modifyTask->dependedTaskList = NIL;
 	modifyTask->upsertQuery = upsertQuery;
+	modifyTask->requiresMasterEvaluation = requiresMasterEvaluation;
 
 	return modifyTask;
 }
@@ -1132,6 +1135,7 @@ RouterSelectTask(Query *query)
 	task->anchorShardId = shardId;
 	task->dependedTaskList = NIL;
 	task->upsertQuery = upsertQuery;
+	task->requiresMasterEvaluation = false;
 
 	return task;
 }

src/backend/distributed/utils/citus_clauses.c

@@ -28,6 +28,32 @@ static Expr * citus_evaluate_expr(Expr *expr, Oid result_type, int32 result_typm
 								  Oid result_collation);
 
 
+/*
+ * Whether the executor needs to reparse and try to execute this query.
+ */
+bool
+RequiresMasterEvaluation(Query *query)
+{
+	ListCell *targetEntryCell = NULL;
+
+	foreach(targetEntryCell, query->targetList)
+	{
+		TargetEntry *targetEntry = (TargetEntry *) lfirst(targetEntryCell);
+
+		if (contain_mutable_functions((Node *) targetEntry->expr))
+		{
+			return true;
+		}
+	}
+
+	if (query->jointree && query->jointree->quals)
+	{
+		return contain_mutable_functions((Node *) query->jointree->quals);
+	}
+
+	return false;
+}
+
 /*
  * Looks at each TargetEntry of the query and the jointree quals, evaluating
  * any sub-expressions which don't include Vars.

src/backend/distributed/utils/citus_outfuncs.c

@@ -458,6 +458,7 @@ _outTask(StringInfo str, const Task *node)
 	WRITE_BOOL_FIELD(assignmentConstrained);
 	WRITE_NODE_FIELD(taskExecution);
 	WRITE_BOOL_FIELD(upsertQuery);
+	WRITE_BOOL_FIELD(requiresMasterEvaluation);
 }
 
 

src/backend/distributed/utils/citus_readfuncs_94.c

@@ -1418,6 +1418,7 @@ _readTask(void)
 	READ_BOOL_FIELD(assignmentConstrained);
 	READ_NODE_FIELD(taskExecution);
 	READ_BOOL_FIELD(upsertQuery);
+	READ_BOOL_FIELD(requiresMasterEvaluation);
 
 	READ_DONE();
 }

src/backend/distributed/utils/citus_readfuncs_95.c

@@ -1507,6 +1507,7 @@ _readTask(void)
 	READ_BOOL_FIELD(assignmentConstrained);
 	READ_NODE_FIELD(taskExecution);
 	READ_BOOL_FIELD(upsertQuery);
+	READ_BOOL_FIELD(requiresMasterEvaluation);
 
 	READ_DONE();
 }

src/include/distributed/citus_clauses.h

@@ -14,6 +14,7 @@
 #include "nodes/nodes.h"
 #include "nodes/parsenodes.h"
 
+extern bool RequiresMasterEvaluation(Query *query);
 extern void ExecuteMasterEvaluableFunctions(Query *query);
 
 #endif /* CITUS_NODEFUNCS_H */

src/include/distributed/multi_physical_planner.h

@@ -141,6 +141,9 @@ typedef struct MapMergeJob
  * as compute tasks; and shard fetch, map fetch, and merge fetch tasks are data
  * fetch tasks. We also forward declare the task execution struct here to avoid
  * including the executor header files.
+ *
+ * NB: Changing this requires also changing _outTask in citus_outfuncs and _readTask
+ * in citus_readfuncs to correctly (de)serialize this struct.
  */
 typedef struct TaskExecution TaskExecution;
 
@@ -162,6 +165,7 @@ typedef struct Task
 	uint64 shardId;                /* only applies to shard fetch tasks */
 	TaskExecution *taskExecution;  /* used by task tracker executor */
 	bool upsertQuery;              /* only applies to modify tasks */
+	bool requiresMasterEvaluation; /* only applies to modify tasks */
 } Task;